Siemens siprotec 7SA522 User Manual page 114

Configuration
Filtering / Contact
Chatter Suppres-
sion
Transformer Tap
Changer (TxTap)
5-16
also be set (see margin heading "Filtering/Contact Chatter Suppression" below), is
only effective for the intermediate (= undefined position) indication. Hence, briefly un-
defined conditions or contact chattering will not lead to an alarm; however, defined
changes in the condition (final positions) are immediately reported.
Figure 5-13 Information properties — example for information type "Double Point Indication"
(DP)
For input indications (single point indications 63, double point indications '3), filter
times may be entered (pick-up and drop-out delays) to suppress momentary changes
in potential at the binary input (e.g. contact chatter), refer also to Figure 5-12 and 5-
13. Filtering occurs during an input change of state, with the same setting values
whether coming or going. Information is only distributed when the new state continues
to exist after a preset time interval (in milliseconds). The setting range is from 0 to
86,400,000 ms, or 24 hours. Whether or not the filter interval is restarted for each
change of state during the filtering (filter re-triggering) is selectable.
It is also possible to set chatter suppression for each indication (Figure 5-12 and 5-13).
The contact chatter settings, themselves, are set the same for all input indications (see
Sub-section 5.2.7).
The transformer tap changer position is communicated, via binary inputs, in a speci-
fied encoding format (maximum of 62 positions). Only binary inputs that are in direct
order with regard to numbering can be used.
For the encoding formats available (binary code, BCD code, "1 of n" code), four set-
tings (number of positions, number of bits, display offset, and position change) may be
programmed. Their bit pattern corresponds to an individual transformer tap changer
position which is represented in the device display and in the indication buffers (Figure
5-14).
7SA522 Manual
C53000-G1176-C119-2